Signobs to i



Patented a... s, 1932 MAX naeanoan annrzuonn'cunaamo, or nnssau m ANHALT, GERMANY, AS-

SIGNORS TO I. G. FABIBENINDUSTBIE AKTIENGESELIQSCHAFT, F IRANKIOBT-ON- ran-mam, csmnr o LLuLosn Esrans or monomc acme Io Drawing. Application filed. October 25, 1927-, Serial No. 228,689, and in Germany October 28, 1938.

process are colloidally has been pressed I threefold of th course of the reaction may be in uenced by The present invention relates to a process of preparing cellulose esters of inorganic acids and to the new compounds obtainable thereby.

organic acids are obtainable by causing an alkali cellulose to reactvwith a chloride of an inorganic acid. The reaction occurs especially easily when using chlorides of po valentinorganic acids as, sulfuric or phosphoric acid. 7

The cellulose esters obtained by the new dispersed in the presence of water. They are useful for various purposes, e. g. as impregnating agents.

According to the conditions of the reaction different degrees of esterification of the cellulose are obtainable and the reaction products difier with respect to colloidal dispersion, conductivit and mechanical properties.

The speed of the reaction, the yield and the composition of the. ester produced depend on the character of the acld chloride and the nature of the alkali cellulose. With chlorides for instance, of

- of strong acids the reaction proceeds with eat energy and with chlorides of more eebleacids and alkali cellulose reacts slowl The reactivity of the alkali cellulose depen s on the manner in which it is previously treated. The best yield and the highest degree of esterification are achieved when cotton is used which has been swollen for at least four hours by means of a sodiumhydroxide solution of 40 per cent strength at about 10C. and until its weight is double or e original wei ht.

choice of the parent material, by the concentration of the alkali hydroxide solution and by the duration of the treatment of the cellulose with the alkali,-by the use of diiierent proportions and diiferent conditions of aggregation of the acid chloride, by regulating the reaction tem erature and by using indifferent media or the reaction.

The following examples illustrate the in-' vention without limiting it, the parts bemg by weight:

1. 100 parts of bleached cotton-linters are swollen. in sodium hydroxide solution of 40 The per cent strength, while cooling with a mixture of ice and salt. After 4 hours the cotton is pressed until its weight is 300 parts. The

soda-cellulose thus obtained is introduced in We have found that cellulose esters of msmall portions into an ice-cold solution of 160 parts of phosphorous-oxychloride in 900 parts of benzene. The heat evolved first raises the temperature of the benzene to the boiling, pointand then the reaction takes a gentle course and a tough magma settles to the bottom of the vessel. After 12 hours the supernatant liquid is drawn off and the dewlth a mixture of ice and salt. After 4 hours the cotton is pressed until its weight is 400 parts and introduced'insmall portions into a mixture of 1800 parts of benzene and 220 parts ofsulfuryl chloride. There is produced a cellulose-sulfuric acid ester which is worked up as described in Example 1. It is a pure whitish body colloidally dispersed by water and not hygroscopic; it contains 60 per cent of S0 What we claim is:

1. e process which comprises causing an alkali cellulose to react with an oxygen containing chloride of an inorganic acid.

2. The process which comprises causing an alkali cellulose to react with an oxygen containing chloride of an inorganic acid in the presence'of an inert diluent.

3. The process which comprises causing an alkali cellulose to react with an oxygen containing chloride of a polyvalent inorganic acid in the presence of an inert diluent.

4. The process which comprises causing an alkali cellulose to'react with an oxygen conminis chloride as sulfuric acid in thepres-' ence o benzene.

5. The process which comprises sub'ecting cellulose to the action of a'sodium hy roxide solution of about 40 per cent strength at a temperature of about 10 C. for about 4 hours, pressing out the reaction product until I,

it has about two to four times its original weight and subjecting o 11 containing ch a??? 6. The process which comprises sub'ecting cellulose to the action of a sodium hy ro'xide solution of'.about 40 percent strength at atemperature of about -10"v C. for about 4 hours, pressing out the reaction product until it has about two to four times its original weight and, subjecting it to the action of an 02: en containing ch oride of an inorganic ace in the presence of benzene. v

7. The process which comprises subjecting 100 parts of cellulose to the action of a sodium hydroxide solution of about 40 per cent strength at a temperature of about 10 C. for about 4 hours, pressing out the reaction roduct until it has about two to four times its original weight and subjecting it to the action of about 220 parts of sulfuryl chloride in the presence of about 1800 parts of ben- 8. 'As new articles of manufacture, stable cellulose esters of inorganic acids, said esters being colloidally dispersed by water.

9. As new articles of manufacture, stable cellulose esters of polyvalent inorganic acids, said esters being colloidally dispersed by water.

10. As a new article of manufacture, the A whitish colored non-hygroscopic cellulose ester of sulfuric acid, containing 60 er cent of S0,, said ester being colloidally ispersed by water an alkali cellulose'to react with an oxygen containing chloride of phosphoric acid in the presence of benzene. I

12. As new articles of manufacture, the stable cellulose esters. of sulfuric acid, said esters being colloidally dispersed by water.

A whitish colored cellulose ester of hosphoricesters'being colloidally tures. 4 a

13. Asnew articles of manufacture, the

lspersed by water. 414. As a new article of manu acture, the

stable cellulose esters of (phosphoric acid, said acid containing 16% of P0,, said ester being colloidally dispersed by water.

In testimony whereof, we aflix' our signa- MAX IHAGEDORN, 'EUGEN GUEHRING.

it to the actionof' an oride of an inorganic.

11. The process which comprises causing 

